In radio communication networks, such as the Long Term Evolution (LTE) or the LTE-Advanced (LTE-A) of the 3rd Generation Partnership Project (3GPP), network planning may comprise the use of a distributed antenna system (DAS) also known as a co-operative antenna system. A proposal have been made to cover environments of otherwise insufficient radio coverage with the DAS, where instead of covering an area 100 by only one base station 102 (or Node B (NB) as specified in the LTE) as depicted in FIG. 1A, the same coverage 100 is provided by multiple base stations 104A to 104D as illustrated in FIG. 1B.
The base stations of the DAS co-operate with each other via a backhaul link such as a transport medium or an X2 interface as in the specifications of the LTE. The control of the co-operation between the base stations 104A-104D in FIG. 1B may be performed by a controller, although not shown in the Figure. The controller may be located separately from the base stations or integrated within one of the base stations.
However, there are challenges related to a configuration of the DAS, such as how to keep the interference between the cells covered by the base stations as small as possible. In order to enable interference-free communication between user terminals and the base stations of the DAS, the controller or each of the base stations need a complete channel knowledge of each of the links between the user terminals and the base stations. Without such information, the interference may become a significant bottleneck for the efficiency of a mobile radio communication employing the DAS. However, the exchange of full channel information requires intensive backhaul usage in the network. Thus, it is important to provide a solution for efficiently minimizing inter-cell interference without the intensive backhaul usage.